Is it a secret? Well... It depends on your situation I guess. If my family, that is pretty traditional is some aspects, knew I read yaoi... it would not be pretty. I do have a friend that knows I read stuff, but she thinks its shonen ai :P In my case, I don't mind keeping things a secret because I know that I am the only one that would understand yaoi around me.
I do know some people are really open about it, so for them it is not a secret really.
In your case, you can keep it a secret and not feel bad too. Its not like, a life changing secret. However, if your inner fujoshi plays a big role in your life and to you it is important for your bf to know that part of you, then ease him to the subject by slowly introducing shonen ai vibes to situations, like choosing to watch a movie with BL secondary themes and see how he aboards it....
Thats what I think at least :P
Sorry, it's not a request. I'm just wondering is enjoying read yaoi considered as a secret, like watching porn? I mean I'm a girl and don't know how to tell my boyfriend that I enjoy read stories about lovey dovey gay couples. lol. ⁄(⁄ ⁄·⁄ω⁄·⁄ ⁄)⁄